1. Field of the Invention
The present invention relates to a polygonal prism, and in particular, to a polygonal prism that can be used to convert an incoming ray of light into separate light rays.
2. Description of the Prior Art
The advancements in technology have made laser appliances useful for a wide variety of applications. Examples include laser levelers for use in marking lines in engineering work, and optical instruments or lenses for survey instruments. A polygonal prism is a basic part of these laser devices.
Conventional polygonal prisms are typically provided in the form of two pieces (e.g., a triangular three-dimensional piece and a pentagonal three-dimensional piece) that are glued together to form the polygonal prism. Selected planes or surfaces of the two pieces are coated with semi-reflective film or fully reflective film to alter the path of a light beam that is directed at selected planes or surfaces of the polygonal prism. Specifically, the incident (i.e., incoming) light is refracted or reflected to change the directions of the light, so that the polygonal prism outputs a plurality of light beams that are emitted at desired and precise angles with respect to each other.
Unfortunately, precision in the bonding of the two prism pieces is critical. Specifically, the two prism pieces must be bonded precisely before undergoing precision polishing. In addition, for the emitted light outputs to be accurate, certain surfaces or planes of the two prism pieces must be precisely parallel to each other after the two prism pieces are bonded together. Unfortunately, this precise bonding can be difficult and expensive to accomplish.